The institution of Corpus Christi as a feast in the Christian calendar resulted from approximately forty years of work on the part of Juliana of Liège, a 13th-century Norbertinecanoness, also known as Juliana de Cornillon, born in 1191 or 1192 in Liège, Belgium, a city where there were groups of women dedicated to Eucharistic worship. Guided by exemplary priests, they lived together, devoted to prayer and to charitable works. Orphaned at the age of five, she and her sister Agnes were entrusted to the care of the Augustinian nuns at the convent and leprosarium of Mont-Cornillon, where Juliana developed a special veneration for the Blessed Sacrament.[2]

She always longed for a feast day outside of Lent in its honour. Her vita reports that this desire was enhanced by a vision of the Church under the appearance of the full moon having one dark spot, which signified the absence of such a solemnity.[3][4] In 1208, she reported her first vision of Christ in which she was instructed to plead for the institution of the feast of Corpus Christi. The vision was repeated for the next 20 years but she kept it a secret. When she eventually relayed it to her confessor, he relayed it to the bishop.[5]

Hugh of St-Cher travelled to Liège as Cardinal-Legate in 1251 and, finding that the feast was not being observed, reinstated it. In the following year, he established the feast for his whole jurisdiction (Germany, Dacia, Bohemia, and Moravia), to be celebrated on the Thursday after the Octave of Trinity (one week later than had been indicated for Liège), but with a certain elasticity, for he granted an indulgence for all who confessed their sins and attended church "on a date and in a place where [the feast] was celebrated".[8]

Jacques Pantaléon of Troyes was also won over to the good cause of the Feast of Corpus Christi during his ministry as Archdeacon in Liège. It was he who, having become Pope as Urban IV in 1264, instituted the Solemnity of Corpus Christi on the Thursday after Pentecost as a feast for the entire Latin Rite, by the papal bullTransiturus de hoc mundo.[2][9] The legend that this act was inspired by a procession to Orvieto in 1263 after a village priest in Bolsena and his congregation witnessed a Eucharistic miracle of a bleeding consecrated host at Bolsena has been called into question by scholars who note problems in the dating of the alleged miracle, whose tradition begins in the 14th century, and the interests of Urban IV, a former Archdeacon in Liège. Though this was the first papally imposed universal feast for the Latin Rite,[10] it was not in fact widely celebrated for half a century, although it was adopted by a number of dioceses in Germany and by the Cistercians, and in 1295 was celebrated in Venice.[11] It became a truly universal feast only after the bull of Urban IV was included in the collection of laws known as the Clementines, compiled under Pope Clement V, but promulgated only by his successor Pope John XXII in 1317.[12][11]

While the institution of the Eucharist is celebrated on Holy (Maundy) Thursday, the liturgy on that day also commemorates Christ's washing of the disciples' feet, the institution of the priesthood and the agony in the Garden of Gethsemane. So many other functions took place on this day that the principal event was almost lost sight of. This is mentioned as the chief reason for the introduction of the new feast, in the Bull "Transiturus." For this reason, the Feast of Corpus Christi was established to create a feast focused solely on the Holy Eucharist.[3]

From 1849 until 1969 a separate Feast of the Most Precious Blood of Our Lord Jesus Christ was assigned originally to the first Sunday in July, later to the first day of the month. This feast was removed from the General Roman Calendar in 1969, "because the Most Precious Blood of Christ the Redeemer is already venerated in the solemnities of the Passion, of Corpus Christi and of the Sacred Heart of Jesus and in the feast of the Exaltaton of the Holy Cross. But the Mass of the Most Precious Blood of Our Lord Jesus Christ is placed among the votive Masses".[17]

The feast of Corpus Christi is one of five occasions in the year on which a diocesan bishop is not to be away from his diocese unless for a grave and urgent reason.[18]

By tradition, Catholics take part in a procession through the streets of a neighborhood near their parish following mass and pray and sing. The Eucharist, known as the Blessed Sacrament, is placed in a monstrance and is held aloft by a member of the clergy during the procession. After the procession, parishioners return to the church where benediction usually takes place.[19]

When instituting the "Year of Faith", Pope Benedict XVI declared that on Sunday, June 2, 2013 at 5 p.m. Rome time, the Pope would preside at an hour of Eucharistic Adoration in St. Peter’s Basilica in the Vatican, in communion with all bishops and with their local diocesan communities around the world.[20] His successor, Pope Francis presided over the special Eucharistic adoration.[21]

On Thursday, 30 May 2013, Pope Francis celebrated Mass at the Basilica of St. John Lateran. Following Mass, he led the traditional candlelight Corpus Christi Procession on foot through the streets of Rome, from the Basilica of St John Lateran to the Basilica of St. Mary Major, just over a mile away. The monstrance with the Blessed Sacrament was carried on the lorry that St. John Paul II began using in 1994 when he could no longer walk the full mile.[22]

Corpus Christi is included in the calendar of a few Anglican churches, most notably the Church of England. The feast is also celebrated by some Anglo-Catholic parishes even in provinces of the Anglican Communion that do not officially include it in their calendars. McCausland's Order of Divine Service, the most commonly used ordo in the Anglican Church of Canada, provides lections for the day. In the Church of England it is known as The Day of Thanksgiving for the Institution of Holy Communion (Corpus Christi) and has the status of a Festival. Although its observance is optional, where kept, it is typically celebrated as a major holy day.

In medieval times in many parts of Europe Corpus Christi was a time for the performance of mystery plays. In Catalonia it is celebrated with the tradition of the Dancing egg, with evidence from the 16th century.

In the village of Castrillo de Murcia near Burgos, the celebration includes the practice of El Colacho (baby jumping).